In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

WA Labor labels iron ore tax 'reckless'

A plan to slug mining giants Rio Tinto and BHP Billiton with higher taxes is economically dangerous and fiscally reckless, the West Australian opposition says.

Brendon Grylls ousted Terry Redman from the Nationals WA leadership this week after three years on the backbench, and wants the companies to pay a $5 per tonne tax on iron ore to help solve the state's financial woes.

Mr Grylls says it is unfair that the 25 cent production rental charge in state agreements with BHP Billiton and Rio Tinto have never been changed since it was created in the 1960s.

But Labor's treasury spokesman Ben Wyatt said it was "hilarious" that Mr Grylls, who had been such a big spender with the Nationals WA's flagship Royalties for Regions fund, could be the one to return the budget to surplus.

Mr Wyatt said the government had capitulated to the "erratic ego" of Mr Grylls and his plan would not solve the state's financial problems - but at least he had one, unlike the premier and treasurer, who respectively had no plan or just wanted to sell assets.

"The only way this erratic idea from Mr Grylls is a coherent financial plan is if you are absolutely financially illiterate," he told reporters on Wednesday.

"It is bad for the economy, it is bad for jobs and it is bad for the long-term finances of Western Australia.